History Main / FirstLawOfGenderBending

* ''Website/SCPFoundation:'' [[https://scp-wiki.wikidot.com/scp-113 SCP-113]] can switch the genders of whomever touches it through a quick but somewhat painful transformation, but it seems to be unable to change them back to their original gender. When a D-Class who had just gone through the transformation was given SCP-113 again, they ended up suffering liver and kidney failure and died after the fact. Subjects who had much greater gap between exposures managed to survive the re-exposure, but the transformations they experience are random and don't have to do with their sex.

* Inversion: The Sailor Starlights from ''Anime/SailorMoon'' they spend significantly more screen time in male identities, to various degrees, with the handwaving that this makes their act of posing as pop idol singers looking for a (female) lost love more convincing. They may or may not have abandoned their male identities in the finale when they left Earth for their home planet. Of course, the show is [[{{shojo}} aimed at girls]]... This is, however, only present in the anime; in the [[Manga/SailorMoon manga]], they're just cross-dressing women and much less prominent characters.

* ''LightNovel/{{Kampfer}}'s'' Natsuru is a boy who is forced to go through a temporary transformation to take part in a secret tournament of female-only fighters. He is the only character who changes sex, while the others merely transform into violent alter-egos. The change is triggered in the presence of other fighters, and later he takes control of it, but Natsuru is very often forced to maintain his female persona.

* Discussed and explained in ''LightNovel/NoGameNoLife'''s light novel. Sora realizes that the Elves' gender changing magic pretty much substitutes the Y chromosone with a clone of the X chromosome[[labelnote:note]][[ArtisticLicenseBiology Realistically]], this would express every recessive gene on that chromosome, almost certainly producing debilitating if not fatal birth defects.[[/labelnote]], so changing back is impossible since the Y chromosome no longer exists.

* One of the reincarnated souls in ''LightNovel/SoImASpiderSoWhat'' is Katia, who in her previous life was the ClosetGay male student Kanata, and is initially distraught that out of every person in his class to reincarnate, only he switched genders. Since the gender-swapping came about via reincarnation there's not much to be done about it, and while Kanata does initially experience some dysphoria and continue to identify as male for a time, eventually he fully assumes the persona of Katia and identifies completely as a girl, literally losing the last semblance of his male identity during a plot conflict. Being able to more openly express his sexuality [[JumpingTheGenderBarrier as a heterosexual woman]] is one motivator for accepting the change, especially since he lucked out enough to reincarnate in the same time and place as a male classmate he'd had a crush on.

* Happens to Danblf in ''LightNovel/SheProfessedHerselfPupilOfTheWiseMan''. One night he messed around with a cosmetics case he bought for his in-game character, creating a female avatar that fit his tastes, and fell asleep before he could cancel and log out. Next thing he knew, he woke up in the game, in standard {{Isekai}} fare, as the girl he designed, instead of the old wizard he had played as for the longest time. Of course, now that the cash shop is closed, and he can't take anyone else's cosmetics cases (they're bound to the player), he's stuck as a girl, going by the name Mira, learning how being a lady works (with endless jokes about bathroom trips), and trying to keep people from finding out about his humiliating fate. Those who do find out tend to find this utterly hilarious.

** The "rules" of Ranma's curse are biased in favor of the Law. "Cold" water will turn Ranma into a girl, but pretty much any temperature below body temperature will suffice. Turning back into a boy requires genuinely ''hot'' water. Simply warm water won't do it, so she is usually limited to two options: taking a hot bath or obtaining a kettle of just-boiled water, which Akane seems to supply quite often. Ranma will generally attract [[MurphysLaw whichever temperature water is the most troublesome at the moment]], and since Ranma was born male, this usually translates to cold water and this Law.

This trope may also reflect the fact that, historically, transwomen[[note]]A person born into a male body who identifies as female[[/note]] seeking treatment were more common than transmen seeking treatment, so transwomen had comparatively more visibility.

** The "rules" of Ranma's curse are biased in favor of the Law. "Cold" water will turn Ranma into a girl, but pretty much any temperature below body temperature will suffice. Turning back into a boy requires genuinely ''hot'' water. Simply warm water won't do it, so she is usually limited to two options: taking a hot bath or obtaining a kettle of just-boiled water, which Akane seems to supply quite often. Also, the curse seems to make water obey the RuleOfFunny and the RuleOfDrama. Ranma will generally attract whichever temperature water is the most troublesome at the moment (and since Ranma was born male, this usually translates to cold water and this Law).

* ''[[Manga/OnimaiImNowYourSister Onimai: I'm Now Your Sister]]'': The story is focused on Mahiro being turned from a college-aged man to a middle school-aged girl, courtesy his TeenGenius sister's mad science. The effects of the drug that transformed him are strictly temporary, however every time they would start to wear off it's at a moment that would be horrifically inconvenient for Mahiro and requires him to take another dose to stay a girl for longer. The first time it happened was when he, his sister Mihari, her friend Kaede, and Kaede's younger sister Momiji, were in a hot spring together.

** Once Ranma acquires his [[SexShifter gender-changing]] {{curse}}, no attempt at curing it works, at least not permanently. Further, many fans have observed that he seems to attract water (which triggers the change) as easily as fiancées and rivals. However, situations where Ranma could be [[ShapeshifterModeLock rendered permanently female]] ''also'' are undone, so the Law is still overruled by StatusQuoIsGod.

* Creator/MarvelComics' shapeshifter character Courier took on a female form during a time travel adventure with Gambit, as part of a ruse to investigate Mister Sinister (then acting as an obstetrician.) Sinister learned that his patient was a shapeshifter, and managed to extract that ability for his own use. Sinister (not knowing Courier's true sex) inadvertently left Courier permanently female as a side effect of this process.

* ''[[Manga/OnimaiImNowYourSister Onimai: I'm Now Your Sister]]'': The story is focused on Mahiro being turned from a college-aged man to a middle school-aged girl, courtesy her TeenGenius sister's mad science. The effects of the drug that transformed him are strictly temporary, however every time they would start to wear off it's at a moment that would be horrifically inconvenient for Mahiro and requires him to take another dose to stay a girl for longer. The first time it happened was when he, his sister Mihari, her friend Kaede, and Kaede's younger sister Momiji, were in a hot spring together.

* Played with in ''VisualNovel/{{Happiness}}!'', where [[WholesomeCrossdresser Jun]] is turned into a girl. He's virtually identical looking anyway, and it only causes lots of magic-related difficulties before he decides to turn back. This might be a simple ShoutOut to the original game, where it was related to removing a RoadCone from more openminded fans.

* Mashiro Ichijo of ''Manga/AfterSchoolNightmare'' was born male above the waist and female below. Mashiro starts out identifying as a male but struggles with his femininity. [[spoiler: Towards the end of the series he accepts his femininity and chooses to be female. The series ends with the revelation that Mashiro's male and female "halves" were actually a pair of HalfIdenticalTwins struggling for survival in the womb; the female twin lives.]]

* ''LightNovel/{{Kampfer}}'s'' Natsuru, after being turned into a girl to take part in a secret tournament of female-only fighters. He is the only character actually afflicted with a gender change, while the others merely transform into violent alter-egos. The change is triggered in the presence of other fighters, and also at will (once mastered), but Natsuru is very ''very'' often forced to maintain his female persona.

* In ''Anime/TheVisionOfEscaflowne'', [[spoiler: Dilandau]] started off as a girl [[spoiler: (actually Allen Schezar's long-lost younger sister)]], and was kidnapped and turned into a boy through a series of horrific {{Magitek}} experiments by the Zaibach Empire. Later, he turns back into a girl...and it's implied that she stays that way. This plotline was AdaptedOut of both the manga and the OVA, [[GenderFlip where said character was a girl and boy, respectively]], and never changed sex.
* ''Manga/BokuGirl'' tends to tip the scales in favor of Mizuki's female form, with him spending more time and seemingly getting more fulfilment than he did as a male. [[spoiler:He ultimately decides to stick with the change by the end. Similarly to ''Kashimashi'' there is strong evidence that Mizuki was a transgender girl even before the change, albeit far more closeted because of his father's influence.]]

* Zig-zagged in ''Manga/OsananajimiwaOnnanokoniNaare'': The fairy Sylphie [[EnforcedTrope feels obligated]] to make the protagonist Iori be a girl. However, by total coincidence, Iori is uncommonly ResistantToMagic, enough to change back [[HeroicWillpower so long as he can will himself to]]. What ensues is a bitter stalemate of Iori changing backing and forth, with [[FailureIsTheOnlyOption neither able to settle the issue permanently]]. [[spoiler:After an EnemyMine to prevent Sylphie's mother from put the Law in effect via [[FakeMemories extreme]] [[DeathOfPersonality measures]], the story ends with Iori and Sylphie [[AndTheAdventureContinues continuing their rivalry indefinitely]].]]

** SmugSnake Edwin Odesserion ends up as a woman after using a scroll he thought would turn him into a lich. While he does manage to turn back in a guy later in the game, in the epilogue an encounter with [[GodModeSue Elminster]] turned him back into "Edwina", who's now a barmaid (In Waterdeep) and a "bitter, bitter woman".[[note]]Since becoming a woman is a possible effect of a scroll mishap in D&D 3.0, s/he may have found an actual lich-turning scroll and just messed up during the casting.[[/note]]
** A permanent sex change is also one of the possible results of a Wild Mage's spell failure. While it's possible to reverse the process with ''another'' spell failure, given that the game rolls percentage to determine the effects of wild magic, the odds are fairly slim.
* Averted in [=MUDs=], where one of the standard status effects is a Gender Bender (which really doesn't do anything in-game except change your pronoun), which affects both genders equally and wears off in a few minutes.

->''"Once a girl has been created, circumstances will conspire to keep her a girl."''

Not only are male-to-female {{Gender Bender}}s a lot more common than their female-to-male counterparts, they are also a lot more ''permanent''. One might think that the same AppliedPhlebotinum that can change a male into a female should just as easily be able to do the opposite, but that's rarely the case in fiction-- most characters who try to reverse a male-to-female Gender Bender will learn that FailureIsTheOnlyOption.

There are many reasons for this. Even if the phlebotinum ''is'' ordinarily reversible there will be a PhlebotinumBreakdown or something ''else'' will prevent the character from simply switching the gender-bender into reverse. Perhaps ''he's'' become the only person who can protect the Earth with ''her'' [[SuperGenderBender gender-based superpowers]]. Perhaps ''she's'' fallen in love with ''his'' best friend after JumpingTheGenderBarrier ([[TheMindIsAPlaythingOfTheBody the mind is a plaything of the hormones]], after all). Maybe a KidFromTheFuture triggered her inner MamaBear and she doesn't want to do anything that would [[RetGone prevent that child from being born]] (the possibility that ''he'' could have been the kid's ''father'' all along is [[FridgeLogic almost never considered]]). Or maybe the EvilutionaryBiologist [[HollywoodScience responsible for]] overprinting [[LegoGenetics half of his DNA]] simply forgot [[NoPlansNoPrototypeNoBackup to make a backup copy of that pesky Y chromosome.]]

Regardless of its in-universe rationale, the First Law is usually enforced because StatusQuoIsGod: When the original sex change is a central tenet of the premise, then it will ''never'' be (permanently) reversed because the series simply [[AnthropicPrinciple wouldn't have happened without it]]. If the series has a finite length, such an event might be saved for its GrandFinale ... [[{{Jossed}} or not]]. On the other hand, if the sex change is ''not'' a central element of the series, it's probably just the plot of one-off episode and will be [[ResetButton reversed quickly]] (perhaps to deliver a AnAesop about walking a mile in another "man's" shoes). If the work is a webcomic called ''The Amazing Girl-Boy's Adventures in Femininity'', expect the First Law to be enforced. If one episode of a KidCom called ''Homeroom Genie'' involves the JackassGenie turning Zach into Zoe to teach him a lesson? Not so much.

Many applications of the first Law carry UnfortunateImplications by trading on the assumption that becoming a woman carries an inherent demotion, punishment, or loss of status. Even the most feminist TakeThat against men may unconsciously support this DoubleStandard if it assumes that a HumiliationConga is inevitable if you put a HandsomeLech [[ThirdLawOfGenderBending in skirts.]] (In these cases expect the author to avert NoPeriodsPeriod in unfortunately graphic detail.) In contrast, female-to-male gender benders are not only less common, but are typically resolved quickly and easily, ultimately reinforcing the woman's original femininity because WomenAreWiser. And since MostWritersAreMale and BeautyIsNeverTarnished the very forces aiding the restoration of her gender will work against him restoring his because just that much more [[FanService pulchritude]] to go around if she gets restored and he doesn't. And if the gender-bent man refuses to act in gender-appropriate ways, then who cares? {{Tomboy}}s have always been more popular than sissies.

Before you ask, there is indeed a SecondLawOfGenderBending, and even a ThirdLawOfGenderBending. They may or may not overlap with the First Law. See ManIFeelLikeAWoman for an example of why some (ex-)men may not want to change back.

* ''Onimai: I'm Now Your Sister'': The story is focused on Mahiro being turned from a college-aged man to a middle school-aged girl, courtesy her TeenGenius sister's mad science. The effects of the drug that transformed him are strictly temporary, however every time they would start to wear off it's at a moment that would be horrifically inconvenient for Mahiro and requires him to take another dose to stay a girl for longer. The first time it happened was when he, his sister Mihari, her friend Kaede, and Kaede's younger sister Momiji, were in a hot spring together.

* Played with in ''VisualNovel/{{Happiness}}!'', where [[WholesomeCrossdresser Jun]] is turned into a girl. He's [[{{Gainaxing}} virtually]] identical looking anyway, and it only causes lots of magic-related difficulties before he decides to turn back. This might be a simple ShoutOut to the original game, where it was related to removing a RoadCone from more openminded fans.

* ''Wiki/SCPFoundation:'' [[https://scp-wiki.wikidot.com/scp-113 SCP-113]] can switch the genders of whomever touches it through a quick but somewhat painful transformation, but it seems to be unable to change them back to their original gender. When a D-Class who had just gone through the transformation was given SCP-113 again, they ended up suffering liver and kidney failure and died after the fact. Subjects who had much greater gap between exposures managed to survive the re-exposure, but the transformations they experience are random and don't have to do with their sex.

* In ''Anime/TheVisionOfEscaflowne'', [[spoiler: Dilandau]] started off as a girl [[spoiler: (actually Allen Schezar's long-lost younger sister)]], and was kidnapped and turned into a boy through a series of horrific {{Magitek}} experiments by the Zaibach Empire. Later, he turns back into a girl...and it's implied that she stays that way. (This only applies in the anime version; in the OVA the character was male from the start, and in the manga, the character started out as a female and stayed that way the whole time.)

* Vampire Guilt-Na-Zan of ''Manga/VampireDoll'' seems to be doomed to be stuck as
a girl because the person who transformed him is a jerk with no interest in reversing it. [[spoiler:He ultimately does in the end.]] {{Lampshade|Hanging}}d in one of the omake comics:

* Vampire Guilt-Na-Zan of ''Manga/VampireDoll'' seems to be doomed to this fate, mainly because the person who transformed him is a MagnificentBastard. {{Lampshade|Hanging}}d in one of the omake comics:
-->'''Kyoji:''' "Thus Guilt-Na obtained the treasure of "friendship", much more precious than becoming a man."
-->'''Guilt-Na:''' ''"You're not going to change me back, are you?!"''
** Ultimately, the way the series deals with the First Law is [[spoiler:aversion, at the end of the Manga.]]

** Among many supporting characters with their own curses, one other (Herb) has the same curse as Ranma, but no female is known to have a curse that makes her male. In fact, male cursed characters vastly outnumber female ones, at a ratio of 8[[note]]Ranma Saotome (girl), Genma Saotome (panda), Ryoga Hibiki (pig), Mousse (duck), Pantyhose Taro (faux-demon), Rakkyosai (child), Herb (girl), and Korma and Masala (human man -- their base forms are BirdPeople[[/note]] to 3[[note]]Shampoo (cat), Rouge (Asura), and Kima (EvilTwin of Akane)[[/note]], with the anime featuring two more cursed men[[note]]Kin'nee (Buddhist Priest) and the Frog Hermit (frog)[[/note]] and an obscure videogame called Ranma ½: Byakuran Aika featuring another cursed girl[[note]Arisa Nanjo (cat)[[/note]] as its antagonist.

* In the Italian movie ''Film/LeComiche2'' a male individual accidentally undergoes an undesired breast augmentation. Later he has a second accident and undergoes a sexual reassignment surgery.

There are many reasons for this. Even if the phlebotinum ''is'' ordinarily reversible there will be a PhlebotinumBreakdown or something ''else'' will prevent the character from simply switching the gender-bender into reverse. Perhaps ''he's'' become the only person who can protect the Earth with ''her'' [[SuperGenderBender gender-based superpowers]]. Perhaps ''she's'' fallen in love with ''his'' best friend after JumpingTheGenderBarrier ([[TheMindIsAPlaythingOfTheBody the mind is a plaything of the hormones]], after all). Maybe a KidFromTheFuture triggered her inner MamaBear and she doesn't want to do anything that would [[RetGone prevent that child from being born]] (the possibility that ''he'' could have been the kid's ''father'' all along is [[FridgeLogic almost never considered]]). Or maybe the EvilutionaryBiologist [[HollywoodScience responsible for]] [[LegoGenetics overprinting half of his DNA]] [[NoPlansNoPrototypeNoBackup simply forgot to make a backup copy of that pesky Y chromosome.]]

* ''Webcomic/ElGoonishShive'', while not as casual or frequent about it as ''Webcomic/TheWotch'', certainly pays the Law its dues. According to the rules governing the comic's main sex-changing phlebotinum, only male-to-female sex changes can be made permanent (via [[MisterSeahorse pregnancy]]); female-to-male sex changes, even of someone trapped by pregnancy (for whom it's only even possible afterwards), cannot exceed a 30 day time limit.

** Also, much later, a "seyunolu" ([[HalfHumanHybrid chimera]]) member of the QuirkyMinibossSquad, Vlad, is hit with a TransformationRay and is turned female, but more importantly to him/her, ''human''. "She" has no desire to change back, and since BizarreAlienBiology overrides the time limit (and, implicitly, gender identity), Vladia, as she is now called, is treated as a woman from then on. She actually could change back, but because her original form was A) hidious, and B) in constant pain, she has no incentive to ever do so.
** Moving on from Elliot being a ''double'' victim of this, we get to Tedd. Who probably wouldn't know this was a law: the 'circumstances' usually equate to "Dad's out of town" and "As a girl, I'm ''hot''".
*** And moving even on FARTHER, the "Squirrel Prophet" storyline has Tedd experience his first ''involuntary'' gender change, when his great godmother decides to try doing him a favour, [[https://www.egscomics.com/comic/2014-07-21 with unexpected results]].
*** Eventually Tedd even gains the unique ability to alter his "base" form, and thus can decide to stay permanently as either gender.
*** And just to twist this trope even further, when Tedd is forced to decide which gender he'd rather be if he ''had'' to pick one, [[http://egscomics.com/comic/2017-02-24 he settles on male]].

* In ''Film/TheSkinILiveIn'', a would-be rapist is captured by the father of one of his victims (who happens to be a plastic surgeon) and turned into a woman as revenge.

* Averted by Tiresias, the blind seer of Greek myth, who was turned into a female, and then several years later was turned back into a man.

** SmugSnake Edwin Odesserion ends up as a woman after using a scroll he thought would turn him into a lich. While he does manage to turn back in a guy later in the game, in the epilogue an encounter with [[GodModeSue Elminster]] turned him back into "Edwina", who's now a barmaid (later ending up in [[VideoGame/DragonAgeOrigins Ferelden]] somehow) and a "bitter, bitter woman".[[note]]Since becoming a woman is a possible effect of a scroll mishap in D&D 3.0, s/he may have found an actual lich-turning scroll and just messed up during the casting.[[/note]]

** Among many supporting characters with their own curses, one other (Herb) has the same curse as Ranma, but no female is known to have a curse that makes her male.

* ''Wiki/SCPFoundation:''' [[https://scp-wiki.wikidot.com/scp-113 SCP-113]] can switch the genders of whomever touches it through a quick but somewhat painful transformation, but it seems to be unable to change them back to their original gender. When a D-Class who had just gone through the transformation was given SCP-113 again, they ended up suffering liver and kidney failure and died after the fact. Subjects who had much greater gap between exposures managed to survive the re-exposure, but the transformations they experience are random and don't have to do with their sex.